We have continued to study the differentiation of bone marrow derived stem cells into tissue-specific differentiated cells. We have performed a series of experiments where mice that had previously been transplanted with green bone marrow (BM) underwent middle cerebral artery occlusion (MCAO). The mice were tested for motor coordination and after different survival times they were sacrificed and the brains were sectioned and immunostained with specific markers to see if these colocalize with GFP (i.e. if the cells derived from the BM). Some of the mice received growth factors and control mice received arteficial CSF to see if the migration of BM cells from the circulation into the CNS can be boosted. Our preliminary results show that there are many cells that enter from the circulation and differentiate into neural cells. We are currently testing the use of growth factors to increase the number of these cells. To achieve this we worked out a technique using organotypic brain slices that enables us to test a variety of growth factors in a reasonably short time. At present we are working on evaluating the results of the above experiments.